Condenser



E. F. POTTER Nov. 30 1926.

CONDENSER Filed Oct. 23, 1922 2 Sheets-Sheet l UWENTOR EARL F. POT TE RATTORNEY Nov. 30 1926.

E. F. POTTER CONDENSER Filed 001;. 23, 1922 2 Sheets-Sheet 2 III/[IllaINVENTOR EARL POTTER 5%; ,4

ATMKUEY Patented Nov. 30,- 1926.

" UNITED STATES PATENT OFFICE.

EARL F. POTTER, OF GLENCOE, ILLINOIS, ASSIGNOR T0 KELLOGG SWITCHIBOARDAND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. I

CONDENSER.

Application filed October 23, 1922. Serial No. 596,211.

My invention relates to condensers and has to do more particularly withvariable condensers with an air dielectric, such as are now in generaluse in wireless sets, a nd an object of my invention is theprovision ofan improved condenser of the variable type, which is provided withstructural features which will facilitate assembly of a condenser ofthis type and at the same time provlde an improved condenser structureWl'llCh Wlll permit the ellicient operation of the same.

The condenser of my invention is of the decremeter type, in which therotating plate element and its supporting-shaft as a whole iseccentrically located in relation to the circular fixed plates so thatthe capacity of the condenser may be made to. vary as the square of theangle of rotation of the rotatable element, which, of course, is wellknown in the art.

One of the features of my invention is the provision of a simple buteflicient adJustable mounting means for permitting the condenser of myinvention, when used in association with a panel type mounting to beuniversally adaptable for panels of different thicknesses. Anotherfeature of my invention is the provision of a combined spring frictionaland thrust means for holding the rotatable plate element in any of itsadjustable positions, and for also preventing movement of the rotatableplate element in a direction parallel to its axis, should undue pressurebe applied upon the dial during the manipulation of the rotatable lateelement so as to prevent touching o' the plates and bring about thedischargeof the condenser.

Still another feature of my invention is the association of a Vernieradjustmentelement with the variable condenser element for finer tuningpurposes and its association with the variable condenser rotary ormovable element. These and other features of my invention will be moreapparent by a reading of the specification.

For a more complete understanding of my invention, reference may be hadto theaccompanying drawings, in which like reference characters in theseveral views denote like parts, and in which Fig. 1 isa front elevationof the condenser of my invention;

Fig. 2 is a plan view of Fig. 1;

Fig. 3 is a sectional view alongthe line 3-3 of Fig. l to more clearlyillustrate the shape of the fixed and rotary condenser plates;

Fig. 4 is a sectional view along the line 4-4. of Fig. 1 to clearlyillustrate the rotary tion as illustrated in the accompanying drawings,the condenser comprises a fixed plate element A, a rotatable plateelement B operatively associated with the fixed late element A. I alsoprovide a fixed'plate vernier element Caindependent of the element A andits associated rotatable plate element D, which may be movedindependently of the rotatable element B.

The'fixed plate element A comprises a plurality of semi-circular plates2 of suitable metal such as aluminum, each being provided with orifices3 which are of a size to receive rods 5, 6 and 7. The rods 5, 6, and 7are inserted alternately through the orifices 3 of the plates 2, andspacer washers Referring now more in detail to my inven- 8 and theirends,'which are threaded, have screw-threaded engagement with studs 9and 10 which are provided with suitable tapped orifices to clamp theplates 2 in position upon the rods 5, 6 and 7. The fixed Vernier elementC also comprises a group of semi-circular plates 2, three in number, andwhich are also provided with orifices 3.

An intermediate base 11 of suitable insulation material, such asbakelite, is provided, and orifices 12 in said base 11 in alignment withthe orifices 3 of the plates 2, are adapted to receive rods 13, 14 and15 which pass through said openings 12, their threaded ends havingscrew-threaded engagement with the tapped orifices in the studs 10.Spacer washers 8 are also provided, and the rods 13, 14 and 15alternately pass through saidwashers 8 and the orifices 3-in the tatableelement B associated with the fixed plate portion A of the condenser.The shaft 22 passes alternately through the openings 21 of plates 20 andspacer washers 23, and when the requisite number are slipped upon theshaft 22 its end 22" which is threaded receives a nut 24,,which tightlyclamps them upon the shaft 22. The plates 20 are also provided with ears25 integrally formed therewith, and provided with openings 26 of a sizeto receive a rod 27, which passes alternately through said openings 26and spacer washers 28. The ends of the rod 27 are threaded and areadapted to receive nuts 29 which clamp the free ends 20 of the plates 20in the proper spaced relation to each other, and at the same time holdthe plates 20 in alignment with each other upon the shaft 22.

The rotatable plate element D of the ver-;

nier portion V of the condenser comprises a pair of plates 20 and ashaft 30 upon which the plates 20 are mounted, the plates 20 also beingsuitably spaced from each other by means of spacer washers 128 andclamped upon the shaft 30 by means of a nut 31 which has screw-threadedengagement with threaded end portion 30 of the shaft 30. The free ends20 of the plates 20 are also kept in proper spaced relation with eachother by means of suitable spacer washers 28 and a screw 32 which passesthrough the spacer washers 28 and the openings 26 and a nut 33 which hasscrewthreaded engagement with the screw 32. The screw 32 and washers 28,in addition to holding the plates 20 in fixed spaced relation with eachother, hold the plates 20 in alignment with each other on the shaft 30.

The construction and assembly of the fixed plate elements A and C andthe rotatable plate elements B and D having been described, I willn-owdescribe the assembly .of the elements A, B, C and D as a whole toform the completed condenser of my invention.

The intermediate base 11 is provided with an orifice 35 of a size topermit the insertion of the shaft 30, and with the plates 20 in positionas illustrated in dotted lines in Iflg. 3, the shaft 30 may be moved inposition so as to place the plate 20 in position to register with thespaces 36 between the fixed plates 2 of the element C of the vernierportion V of the condenser. \Vhen the rotatable plate element D is inthis position, a base plate 37 provided with orifices 37' of a size toreceive the threaded end portions of rods 13, 14 and 15 is placed inposition. The protruding threaded ends of rods 13, 14 and 15 receivenuts 38 which clamp the fixed plate element C in position between thebase 11 and plate 37. The shaft 30 which is also provided with a reducedportion 30 rests in an orifice 39 which forms a bearing for one end ofthe shaft 30, and the opening 35 in the base 11 forming anintermediatebearing for the shaft 30. The shaft 22 of the rotatableplate element B is provided with a central orifice 40 extending itslength .,and is of a size to permit it being slipped over the shaft 30of the rotatable plate element D of the vernier portion V of thecondenser, and with the plates 20 'of the rotatable element B in theposition shown in dotted lines in F ig: 3, the said rotatable plateelement B is slipped over the shaft 30.

When the plates 20 of the rotatable element B register with theirrespective spaces 140 between the plates 2 of the fixed plate element A,a top plate 41 having an orifice 42 permits the shaft 22 to extendtherethrough and screws 43 pass through suitable orifices 44 in theplate 41 and have screw-threaded engagement with the studs 9. 'Toprovide clearance for the shafts 22 and 30 of the rotatable elements Band D, a circular area is cut from the fixed plates 2 at the point 144eccentrically displaced with relation to the center of the fixed plate2. The shaft 30 of the rotatable element D of the vernier portion V ofthe condenser extends through the orifice 40 in the shaft 22 whichserves as a bearing for the said shaft 30.

A. combined thrust and frictional leaf spring 45 is provided for therotatable plate element B which is provided with an orifice 46 throughwhich the shaft 30 extends. The spring 45 is arcuate in shape and issecured to the base 11 by means of a suitable screw 47 and nut 48, itsone end being provided with an angular extending tongue 45 which restsin a suitable orifice in the base 11 and prevents rotation of the saidspring 45. The tension of the spring 45 is such as to bear against thebottom face of the shaft.22 to place its face in frictional engagementwith the bottom face of the shaft 22 so that as the rotatable element Bis rotated for tuning purposes it will remain in any position it is setdue to this frictional engagement. The spring 45 also acts as athrust-means as the tension of the spring 45 is such as to force theshaft 22 and its parts as a whole upward in relation to Fig.1, and, ifany downward pressure is exerted upon the shaft 22 the tension of thespring 45 is such as to prevent the shaft from being forced downward andcause the rotatable plates 20 to engage the fixed plates 2 to dischargethe condenser when in use. A suitable dial 50 shown in dotted lines issecured to'the shaft 22 by suitable means to permit the readymanipulation of the rotatable element B and a pair of pin stops 51 and52 are provided which are secured to the plate 41 and are associatedwith the pin 53 secured to the shaft 22 and the engagement of the pin 53with the pins 51 and 52 limits the movement of the rotatable element Bthrough a certain degree of rotation for the usual tuning purposes.

A combined thrust and friction spring 54 is also provided for the shaft30 of the ro- 1 tatable element D of the Vernier portion V of V througha certain degree of rotation. The

spring 54 also serves as a terminal for the rotatable elements B and Dto connect them with the external circuit with which the condenser isconnected.- The rotatable element D of the Vernier portion V isrotatable independent of the rotatable element B, and a knob 60 shown indotted lines in Fig. 1 when grasped by the operator, may be turned, thesaid shaft 30 turnin in the bearing in the shaft 22 formed by t eorifice 40 in the said shaft 22. a From the above description, it iorsupporting maybe seen that when the dial is turned the rotatable elementB is rotated independent of the shaft 30 of the rotatable element D, andwhen the proper tuning is accomplished through the medium of therotatable element B in association with the fixed element A the saidelement B is held in position by means of the spring 45. If a furtherfiner tuning is desired to clarify, the knob is grasped and therotatable element D is rotated until the desired result is obtained. Thesprin 54 is of such tension as to hold the rotata le element D at normal,while the rotatable element B is rotated, and

. of varying thicknesses, and to permit the condenser of my invention tobe used in connection with panelsof varying thicknesses, I provide studsstaked to the top plate 41.

The stud 70 is provided with a threaded ex-' tension 71 and a tappedorifice 72 and nuts 76 are provided WlllCh have screw threadedengagement with the extension 71 of-the studs 70. By referring to Fig. 1of the .drawing, I illustrate one of the adjustable securing means insection, and as there are three of these that are provided similar in:

construction, a detailed description of one will suflice. Asillustrated, I show the securing means adjusted for a maximum thicknessof panel 75 in which the adjustable nut 76 is in its uppermost adjustedposition, and

in which position the panel rests against the face of the nut 76. Ascrew 77 passes through a suitable opening in the panel and hasscrew-threaded engagement with the tapped orifice 72 in the stud 70 tosecure the condenser as a whole to the panel. Now, if a panel whosethickness is less than that illustrated at 7 5 is to be used, the nut, 76 is turned 4 down to adapt the thickness of panel to be used, and whenso adjusted the screw 77 is tightened to secure the condenser to thepanel against movement.

While I have described the variable condenser of my invention in itspreferred form, a

it is to be understood that changes and modifications will readilysuggest themselves by those skilled in the art, and I desire to coverall such changes and modifications as come within the spirit and scopeof the appendcd claims.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. In a device of the character described pair of rotatable elements,mounting plates said elements in fixed relation, studs secured to one ofsaid plates provided with threaded extensions and nuts havingscrew-threaded engagement with said threaded extensions, adjustable uponsaid extensions to permit said device to be secured to varyingthicknesses of mounting anel. 2. In a device of the character escribedincluding a pair of fixed plate elements and a pair of rotatable plateelements, mounting plates for supporting said first and rotatable plateelements in fixed relation with each other studs secured to one of saidplates provided with threaded extensions, nuts having screw-threadedengagement with said threaded extensions, and adjustable upon saidextensions to permit said device to be mounted upon varying thicknessesof mounting panel and screws having threaded en agement with said studsfor securing said evice on said mounting panel. I 3 In a device of thecharacter described a pair of rotatable elements, rotatableshafts forsaid elements, one of said shafts extending through the other of saidshafts and rotatable independently of said other shaft, and individualspring means for each of said shafts, said individual spring means'engaging its associated shaft to hold said associated shaft in any ofits rotatable positions and also to prevent longitudinal movement I ofsaid associated shaft.

4. In a device of the class described, a' pair of rotatable elements, apair of stationary elements, an individual shaft for each of saidrotatable elements and associated to ermit said rotatable-elements to berotated independently of each other, a s ring member for\ preventinglongitudina movement of the shaft of one of said rotatable elementsandto also hold the same in any of its rotatable positions, a mountingplate for said elements, means formed integrally with said spring memberadapted to engage said mounting plate to prevent rotary movement of saidspring member relative to the shaft of said one element. v

5. A device of the class described including mounting members, a pair ofrotatable elements, an individual shaft for each of said rotatableelements adapted to engage each other and to rotatably support saidrotatable elements in said mounting members so that said elements arerotatable independently of each other, an individual spring member foreach of said shafts secured to vsaid mounting members and adapted toengage their associated shafts to prevent longitudinal movement of saidassociated shafts and to also hold said associated shafts in theirrotatable position, and a terminal integrally formed with one of saidspring members to receive an external conductor.

6. A device of the class described" includ ing a pair of rotatableelements, an individual shaft for said rotatable elements, one of saidshafts extending through the other of said shafts but arranged to permitsaid shafts to be rotated independently of each other, a spring memberfor engaging one of said shafts and a spring-member for engaging theother of said shafts, said spring members adapted to prevent.end\visemovement of said shafts and to also hold said shafts and said rotatableelements in any of their rotatable positions, and means formedintegrally with one of said spring members for receiving an externalconductor to close a circuit through said shafts and said rotatableelements.

7. A device of the class described includ-' ing a pair of stationaryelements, a pair of rotatably adjustable elements, an individual shaftforeach of said adjustable elements for adjusting said adjustableelements relative to said stationary elements, said shafts havingcontactual engagementwith each othe to connect said adjustable elementsin circuit with each other but adapted to rotate independently of eachother, and an individ ual spring member for each of said shafts adaptedto engage the end of the shaft to shaft for each of said adjustableelements for adjusting said adjustable elements relative to saidstationary elements, said shafts having contactual engagement with eachother to connect said adjustable elements in circuit with each other butadapted to rotate independently of each other, an individual springmember for each of said shafts adapted to engage the end of the shaft toprevent endwise movement of the shaft and to hold the shaft and itsassociated rotatably adjustableelement in any of their adjustablepositions, and means formed integrally with one of said spring membersadapted to receive an external conductor to close a circuit through saidshafts and said rotatably adjustable elements.

9. A device of the character described including a pair of supportingplates, fixed and movable condenser plates between said supportingplates, a third supporting plate, fixed and movable condenser platesbetween said third supporting plate and one of said first supportingplates, concentric shafts for moving saidmovable condenser plates, and

spring means for maintaining said movable condenser plates in any oftheir rotatable positions.

10. A device comprising three supporting plates, fixed and movablecondenser plates between said supporting plates, a pair of controls foroperating said movable condenser plates, and spring means formaintaining said movable condenser plates in any of their rotatablepositions.

11. A device comprising three supporting plates, fixed and movablecondenser plates between saidsupporting plates, connector shafts foroperating said movable condenser plates, and spring means formaintaining said movable condenser plates in any of their rotatablepositions.

Signed by me at Chicago in the county of Cook and State of Illinois,this 19th day of October, 1922.

EARL F. POTTER.

